Peristaltic pump, use of said pump, guide path for use in a peristaltic pump and a method of lubricating a peristaltic pump

ABSTRACT

The invention relates to a peristaltic pump ( 6 ) for pumping viscous media, and comprises a housing ( 6 A,  6 B) having a wall ( 12 ) against which a hose ( 25 ) is placed, a shaft ( 7 ) that is centrally positioned in the housing and that carries a roller arm ( 13 ) having a roller ( 14 ) adapted to roll against and at the same time locally compress the hose ( 25 ) against the wall ( 12 ). According to the invention a guide path ( 35 ) for the hose and impregnated with lubricant is arranged in the housing of the pump. The invention also concerns an application of such a pump, a guide path for use in such a pump and a method of performing lubrication therein.

TECHNICAL FIELD

[0001] The present invention relates generally to peristaltic pumps thatare preferably used to pump viscous and/or polluted media.

BACKGROUND

[0002] Peristaltic pumps or hose pumps consist of a generallycylindrical housing in which an elastic or flexible hose is placed andarranged in a loop against a portion of the cylindrical wall, wherebythe hose is typically arranged in a loop of about 180°. The hose forms avolume that is divided into a number of pump chambers by a pump unitthat is arranged for rotation on a centrally positioned shaft in thehousing. The pump unit supports one or more rollers or slide shoes thatengage the hose and compress it to thereby divide the hose into suctionand pressure chambers, respectively. On rotation of the pump unit, therollers gradually transport the medium from an inlet to an outletthrough peristaltic action. A major advantage of such a pump is that noparts of the pump other than the hose are in contact with the pumpedmedium, and for this reason hose pumps are used within many areas wherethis is of importance, from pumping sterile liquids in the medicalfield, for instance, to pumping polluted and/or aggressive media orsludge within the industry and other fields.

[0003] Typically, in all such applications the pump unit is providedwith at least two rollers or slide shoes, thereby eliminating the needfor non-return valves. An embodiment of this type is disclosed forinstance in NO 144 977. However, the problem with such pumps is that thenumber of compressions of the hose during one revolution of the pumpunit increases as the number of rollers increases, and that the usefullife of the hose is thus reduced correspondingly.

[0004] In order to increase the useful life of the hose, it is suggestedin SE 357 801 that the hose is arranged in a loop of up to 360°, withthe two ends of the hose positioned on top of each other. The hose isacted on by one single roller having a corresponding length or heightand consequently continuously engaging the hose. In this way, the needfor non-return valves is eliminated, and at the same time the usefullife of the hose may in theory be doubled as compared to a pump havingtwo rollers.

[0005] The peristaltic pumps available on the market all focus onoptimizing certain parameters that are important to the intended use.Thus, pumps to be used for example in the medical field are designed forlow pressure ranges, and generally also with a low suction capacity. Theemployed hoses are generally made of a homogenous material, withoutreinforcement. Instead, priority is given to other features, such asexact dosing, sterility etc.

[0006] On the other hand, pumps that are employed in industry and withinthe building sector, for example for pumping concrete, are dimensionedfor high pressure ranges to transport the respective medium a longerdistance or to a greater height. However, they are practically alwaysstationary and the pumped medium is supplied to the pump in such waythat no powerful suction capacity is needed Since the pumps arestationary, they are moreover of a comparatively heavy and bulky designand thereby basically not suited for use in the field, such as forclean-up operations in nature.

[0007] A considerable contributory cause to the heavy and unwieldydesign is the high demand for tightness of the pump housing, which is aconsequence of the fact that the pumps are traditionally filled with aliquid lubricant, for example glycerine.

[0008] Furthermore, the hose of such pumps is designed to withstand therelatively high pumping pressures without rupture or excessive,elongation. An example of such a hose is given in U.S. Pat. No.3,887,306, where a hose is described that, in addition to a conventionaltensile rigid reinforcement consisting of wires crossing one another ata suitable angle, in certain areas is provided with a reinforcementconsisting of reinforcing threads arranged in the longitudinal directionof the hose. This longitudinal reinforce Kent is positioned in the areawhere the rollers engage the hose and likewise has the purpose ofpreventing excessive elongation of the hose by the action of the rollersagainst the latter.

[0009] A peristaltic pump using pairs of rollers to compress the hose isdescribed in EP 0 889 237 A2. According to this document is suggested ahose design that shall be very durable and in particular shall exhibitgreat resistance to the local stress imposed on it by the rollers. Toachieve this, it is suggested that the hose be made entirely of one andthe same rubber material that shall be resistant to wear and weather. Inthe rubber material, four layers of reinforcement are embedded that areall of the same general structure, having parallel wires of syntheticfibre cord that are preferably helically arranged around the hose. Thesecord layers solely aim to increase the durability of the hose and do notsignificantly contribute to alter the pumping properties thereof.

[0010] However, to our knowledge there has been no development aiming atoptimizing this type of peristaltic pumps in order to make them moreeasy to handle and more suitable for mobile use.

SUMMARY OF THE INVENTION

[0011] The present invention eliminates the above drawbacks in anefficient and appropriate way.

[0012] A general object of the invention is to produce a practicallyuseful solution to the problem of providing a light and easilymaneuverable peristaltic pump that has optimized operational featuresand useful life.

[0013] Accordingly, a basic object of the invention is to find an easyand appropriate way of minimizing the weight and dimensions of aperistaltic pump while simultaneously optimizing its suction capacity aswell as its discharge pressure capacity.

[0014] According to the invention, this is achieved by arranging a guidepath against an inner wall of the pump housing, the guide path beingprovided with an upper surface adapted for supporting the hose and theguide track being impregnated with a lubricant. Hereby, the dimensionsof the pump housing can be considerably reduced since it does not haveto be made extremely tight to enclose a major amount of free-flowinglubricant, as is conventional.

[0015] According to one embodiment of the invention the guide pathconsists of cellular rubber forming a reservoir for the lubricant,whereby a further improved, long-term interval lubrication is achieved.

[0016] According to other embodiments the guide path consists of asupport ramp having an upper surface that is formed with a slope forpositioning the ends of the hose in planes above each other, the slopeis formed as a screw pitch and the roller and the inner wall of the pumphousing are provided with layers of a resilient material, such aspolyurethane.

[0017] According to other embodiments of the invention the length of aroller arm that in the outer end carries a roller for compressing thehose, is linearly adjustable in a radial direction, and a special hosecoupling is used to perform a retraction of the hose towards the pumphousing during assembly. All of these embodiments contribute tofacilitate mounting and dismounting of the very rigid and thick hose inthe pump.

[0018] According to further embodiments of the invention, the hose ofthe pump is formed of different layers to adapt it to the intendedapplication. According to the invention, these layers consist of innerand outer layers of rubber material adapted to be resistant to thesubstances and to the influence they may be subjected to, as well as ofcompression rigid and tensile rigid reinforcement layers, respectively(referred to below as “compression rigid” and “elongation rigid” layers)and a thick layer of highly resilient or elastic material having lowattenuation, serving as the “muscle” of the hose to achieve the desiredsuction capacity of the peristaltic operation and being arranged betweensaid inner and outer layers. Thereby, is obtained a pump that may so tospeak be tailored for different situations requiring optimized suction,pressure and physical properties.

[0019] According to still another embodiment the compression rigidreinforcement layer consists of cord material having cord ofmacrofilament crossing at an angle of about 120°, each at an angle ofabout 60° to the central axis of the hose, and the elongation rigidreinforcement layer consists of tensile rigid cord material of polyestercord crossing at an angle of about 108°, each at an angle of about 54°to the central axis of the hose. Such an embodiment optimizes theresistance to elongation of the hose as well as its ability to springback and to withstand compression.

[0020] According to another embodiment of the invention, the differentlayers of the hose are arranged in an optimal order to provide the bestefficiency possible. Outside the inner durable layer consisting of afirst synthetic material, is arranged a first layer of the compressionrigid cord material, then the layer of highly elastic material, a secondlayer of the compression rigid cord material and, adjacent to the outerdurable layer consisting of a second synthetic material, the layer ofelongation rigid cord material.

[0021] According to a further embodiment of the invention, the hose isdimensioned to provide maximum suction capacity while accepting solidparticles of considerable size in the pumped medium, without beingdamaged thereby. For this purpose it exhibits a relationship betweeninner and outer diameter of <0.56 and the layer of highly elastic orresilient material has a thickness of at least about 30% of thethickness of the hose wall.

[0022] Further embodiments of this first aspect of the invention arespecified in the corresponding, dependent claims.

[0023] According to another aspect of the invention, it is suggested touse a pump according to the invention in mobile equipment for clean-upoperations in remote areas.

[0024] According to yet another aspect of the invention a guide path issuggested that is intended to be arranged in the housing of aperistaltic pump for supporting and guiding the pump hose and at thesame time providing lubricant primarily to the hose and the roller.

[0025] Embodiments of this aspect of the invention are evident from theaccompanying dependent claims,

[0026] According to still another aspect of the invention is suggested amethod to guarantee satisfactory lubrication of the hose and the rollerin a peristaltic pump of mentioned type.

[0027] More specifically, it is suggested according to this aspect thatan intermittent lubrication that is controlled by the engagement betweenthe roller and the hose is accomplished by forming a lubricant reservoirin a yielding guide path for the hose.

[0028] Embodiments of this aspect of the invention are evident from theaccompanying dependent claims.

[0029] These and other objects of the invention are achieved by theinvention as defined in the appended claims.

[0030] Briefly, the present invention provides the following advantages:

[0031] The pump can be designed to be light and easily maneuverable,adapted to mobile equipment; while offering an

[0032] Improved possibility for interval lubrication of the hose and theroller;

[0033] Optimization of the suction capacity of the pump;

[0034] At least maintained discharge pressure capacity; and

[0035] Long useful life;

[0036] Allows comparatively-simple mounting and dismounting of a veryrigid hose in the pump.

[0037] Further objects, features and advantages of the presentinvention, as well as further embodiments thereof, are evident from thedependent claims and from the following description of exemplaryembodiments.

DESCRIPTION OF THE DRAWINGS

[0038] A more detailed description of the invention is given below,taken together with the accompanying drawings, in which:

[0039]FIG. 1 is a perspective view of mobile clean-up equipment using apump according to the invention;

[0040]FIG. 2 is an exploded view of the equipment in FIG. 1,illustrating the main parts of the pump according to the invention;

[0041]FIG. 3 is a schematical cross-sectional view of an embodiment of ahose used in the pump according to the invention;

[0042]FIG. 4A is a schematical illustration of the embodiment of theelongation rigid cord layer in the hose according to FIG. 3;

[0043]FIG. 4B is a schematical illustration of the embodiment of thecompression rigid cord layers in the hose according to FIG. 3,

[0044] FIGS. 5A-B is a perspective and a cross-sectional view,respectively, of the roller arm in the pump according to the invention,and

[0045] FIGS. 6A-C is a perspective, an exploded and a cross-sectionalview, respectively, illustrating a hose coupling in the pump accordingto the invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0046] Referring primarily to FIGS. 1, 2, 3, 4A and 4B the basicprinciples of the invention will now initially be described by means ofa first embodiment. At the same time, the differences compared toprevious designs will be explained.

[0047]FIGS. 1 and 2 illustrate a peristaltic pump 6 according to theinvention in an embodiment as mobile equipment 1 preferably intended forclean-up operations in nature. Examples of such applications areclean-up operations at oil spill and other environmental pollution,often in remote areas not possible to reach with conventional slurryexhausters. In such cases it is required that highly viscous andpossibly polluted media can be sucked up and then be discharged andtransported a considerable distance.

[0048] For this purpose the pump 6 is mounted in a frame 2 forminghandles 3 as well as supports 4 and an attachment for a wheel 5. In thisembodiment the pump 6 can thus be transported as a wheelbarrow and usedat places where there is no roadway.

[0049] The pump 6 is formed by upper and lower housing halves 6A and 6Bthat are supported in the frame 2 and that are assembled by means ofbolt connections 40 at outer connecting flanges 6C, 6D on the housinghalves 6A, 6B. The housing halves form a substantially cylindricalhousing having a wall 12, the inner surface of which forms a supportsurface for a hose 25 that is arranged in a loop in the housing. Morespecifically, the hose 25 is arranged in a loop of more than 360°, i.e.the ends of the hose 25 are crossed, the arrangement as such being knownthrough the initially mentioned document SE 357 801. Using hosecouplings 26, described further below, the ends of the hose are mountedat an inlet 9 and an outlet 8, respectively, at the lower housing half6B and tho upper housing half 6A, respectively, being directed insubstantially opposite directions. This arrangement is in particularlyadvantageous for the described type of clean-up operations.

[0050] Centrally in the housing 6A, 6B is arranged a drive shaft 7 thatis mounted in bearings in the upper housing half 6A as well as in thelower housing half 6B, whereby only the upper bearing 7A is illustratedin detail in FIG. 2. The drive shaft 7 is driven in a way not furtherillustrated by a drive assembly 10 that does not in itself constitutepart of the invention and that is accordingly not further describedhere. However, in the embodiment disclosed herein a hydraulic drive unitis preferably used to drive the pump. A combustion engine or anelectrical motor preferably drives the hydraulic drive unit.

[0051] A roller arm 13 is mounted on the drive shaft 7, fixed to rotatewith the shalt, preferably through a keyway-connection between the shaft7 and a through bore 22 in the roller arm 13. In the outer end, theroller arm 13 carries a roller holder 15 with a roller 14 rotationallymounted therein and adapted to locally compress the hose 25 to producethe peristaltic pumping action upon rotation of the drive shaft 7, inthe way described above. The inner side of the housing 6A, 6B as well asthe roller 14 are preferably covered by a resilient material, such aspolyurethane, to contribute to allowing pollutants in the form of solidparticles of a size of up to 40 mm diameter to pass without damaging thehose 25 or the mechanical parts of the pump 6. To allow relief of thehose 25 during operational interruption and to facilitate mounting ofthe hose the roller arm 13 is radially adjustable with respect to thedrive shaft 7, as will be described further below with reference toFIGS. 5A and 5B.

[0052] Since the ends of the hose are crossed, the hose extends with apitch or slope along the housing wall 12, and in order to support thehose 25 in this path a “support ramp” 35 is arranged adjacent to theinner surface of the housing wall 12 of the lower housing half 6B. Thehose 25 rests against an upper surface 35A of the support ramp 35, whichis consequently performed having a “screw pitch”. The support ramp 35 ismade of a yielding material, for example cellular rubber, to be able togive way during compression of the hose 25 and then return to itsoriginal shape. For the purpose of strengthening the support ramp 35 andof increasing its ability to return to the original shape it ispreferably covered with a not specifically illustrated durable material,such as polyurethane, at all sides except the one 35B facing the roller.

[0053] For this type of pump, lubrication of the hose is essential toobtain a long useful life of the hose. In many previous applications,the lubrication has been solved by making the housing of the pumpcompletely tight and by filling it with a lubricant. However, such asolution results in a heavy and bulky pump that is above all suitablefor stationary operation, and especially not for the above-discussedsituations of oil clean-up in remote areas. In such cases, mobileequipment has to have as low weight as possible and must be easy tohandle and to maneuver. According to the invention, it is thereforesuggested that the support ramp 35 is impregnated with a suitablelubricant that does not affect other materials of the ramp 35, the hose25 or the roller 14. This solution offers an advantageous optimizationof the lubrication interval since, for each revolution lubricant isconveyed from the reservoir of the support ramp. Via the uncovered side35B of the ramp, lubricant is fed to the hose 25 and to the roller 14.Furthermore, this solution contributes to making a comparatively lightand easily maneuverable pump housing design.

[0054] In order to achieve the basic objects, i.e. a strong suctioneffect that allows lifting highly viscous and polluted media, incombination with a high conveying capacity and an appropriate usefullife of the hose, the pump 6 uses a very strong hose 25, i.e. a hosepresenting a strong “muscle” for the peristaltic action and at the sametime a great resistance to high discharge pressures and to the impact ofthe roller. Here, the expression that the hose shall have a strongmuscle means that it shall exhibit a great spring-back force with“dynamical” properties to generate the required negative pressure at theinlet and thereby to provide a large suction capacity. For thesereasons, the hose according to the invention is formed of a series ofdifferent layers giving the hose a combination of different propertiesthat are important to the intended fields of application.

[0055] Thus, in the embodiment illustrated in FIG. 3 the hose 25comprises an inner layer L1 that shall be resistant to the pumpedmedium. In the intended clean-up applications for the pump 6 of theillustrated embodiment, nitrile rubber is a suitable choice of material,but other materials may be present in other applications where otherspecific media are pumped. Outside the first-mentioned layer is arrangedreinforcement in the form of a first compression rigid layer K1 of cordmaterial. The cord material consists of wires crossed in a way furtherspecified with reference to FIG. 4B. This layer K1 above all contributesto providing good spring back properties and a long useful life of thehose 25.

[0056] Outside the first compression rigid layer K1 is arranged the“muscle” of the hose in the form of a layer M of highly elastic orresilient material with low attenuation, providing good spring back andat the same time a long useful life. The material of the “muscle layer”is preferably natural rubber or a material with correspondingproperties. This layer M is the thickest, having a thickness TS of atleast 30% of the wall thickness TV of the hose 25, and thereby it alsocontributes to allowing solid particles of the above given size to passwithout damaging the hose 25.

[0057] Then follows a second compression rigid layer K2 that isadvantageously formed in the same way as the first layer. Then followsreinforcement in the form of an elongation rigid layer E of cordmaterial, again having crossed wires that are here crossed in a way thatis further specified with reference to FIG. 4A. Finally, the hose 25 isprovided with an outer layer L2 of a material resistant to wear, toultraviolet radiation and to substances, such as oil, occurring in theintended application. In the exemplary embodiment where the pump 6 isintended to be used for instance for oil clean-up operations,chlorophrene rubber or alternatively polyurethane is a suitablematerial.

[0058] This general composition of the hose 25, with the mentionedlayers presenting their different properties, is important for obtainingthe desired properties. However, it should be emphasized that it ispossible to vary the exact mutual positions of the differentreinforcement layers K1, K2, E and of the “muscle layer” M in the hose.

[0059] However, performed tests have shown that it is possible to obtainparticularly good results using a hose having a relationship betweeninner diameter D1 and outer diameter DY below 0.56 and a layer M ofhighly elastic or resilient material having a thickness TS that isbetween about 30-35% of the wall thickness TV of the hose 25, especiallyfor hoses having an outer diameter of up to 100-120 mm.

[0060] Below follows an example of one such specific design of the hoseaccording to the invention that in test has shown particularlyadvantageous for the application of the invention illustrated in thedrawings, by clean-up operations in nature. In this case, the hose hadan outer diameter DY of 92 mm and an inner diameter DI of 50.8 mm, i.e.a relationship between DI and DY of about 0.55.

[0061] The composition and the different layers of the hose are clearfrom the below table: POSITION LAYER MATERIAL THICKNESS HARDNESS (fromcentre) L1 Nitrile rubber   4 mm 60 Shore A 1 L2 Chloroprene 2.4 mm 60Shore A 6 rubber M Natural rubber   7 mm 60 Shore A 3 K1 Macrofilament2.6 mm — 2 K2 Macrofilament 2.6 mm — 4 E Polyester   2 mm — 5

[0062] Thus, the wall thickness TV of the hose was 20.6 mm and thethickness TS of the highly elastic layer M was about 34% of the wallthickness TV of the hose.

[0063] As illustrated in FIG. 4A, the polyester cord in the elongationrigid layer E was crossed at a mutual angle β of about 108°, each at anangle λ, of about 54° to the central axis C of the hose. The compressionrigid layers K1, K2, where the cord was crossed at an angle α of about120°, each at an angle γ of about 60° to the central axis C of the hose25, are shown in FIG. 4B.

[0064] With this hose a suction capacity of −1 bar and simultaneously adischarge pressure capacity of 10 bar was achieved in the pump accordingto the invention, at a rotation speed of 45 rotations per minute, andthis well meets the set goals.

[0065] The described design of the hose in turn leads to a very stiffhose that is difficult to mount in the housing and to replace. Thereason for this is partly that the hose is arranged in a 360° loop inthe housing, but moreover the very thick and stiff hose 25 would have tobe completely compressed to be possible to mount between the wall 12 andthe roller 14 that is adapted to continuously engage the hose. Morespecifically, a force of about 700 kp would be required to compress ahose with the composition described in the example.

[0066] For the purpose of eliminating the need for special, very heavytools to achieve this compression of the hose, it is suggested accordingto the invention, as mentioned above, that the roller arm is designedhaving a linearly adjustable length. The design of the roller arm 13 ismost clearly illustrated in FIGS. 5A and 5B, where it is evident thatthe roller arm 13 has a stationary unit that through thekeyway-connection is mounted on the shaft 7, fixed to rotate with theshaft. Said unit comprises a block 18 surrounded by upper and lowerguide plates 19 and 20, respectively, that can be clamped towards eachother by means of clamp bolts 21. In the sides facing each other, theguide plates 19, 20 are provided with guide grooves 19A, 20A forslidable but lockable reception of guide bars 16, 17 extending from theroller holder 15. Thus, the upper and lower guide plates 19 and 20,respectively, are clamped against the slide bars 16, 17 to fix these inposition and thereby to fix the length of the arm after adjustment.

[0067] An adjusting plate 23 engages the rear ends of the slide bars 16,17, i.e. on the opposite side of the pump shaft 7 compared to the roller14. An adjusting screw 24 having a fine pitch extends through theadjusting plate 23 and can be screwed into the block 18 to cause aradial adjustment of the roller holder 15 relative to the pump shaft 7by pressing against the ends of the slide bars. After adjustment thebars are locked by clamping together the guide plates 19, 20 using theclamp bolts 21. Through the fine pitch of the adjusting screw 24, thenecessary force to compress the hose can be obtained without any majorproblem. As hinted above the adjustability is not only important formounting/dismounting, but it is also important to be able to relieve thepressure on the hose during long-time storage. After cold storage, whenthe rubber materials may be brittle, it is advantageous to make a gentlestart-up in the sense that the roller arm is adjusted for only partialcompression of the hose. The pump is then run a number of revolutionsuntil the hose softens, and then the arm is extended for complete hosecompression.

[0068] It is also difficult to mount the thick and rigid hose in thehousing with the described shape of a loop exceeding 360°. Morespecifically, as the hose is positioned against the inner wall 12 duringassembly it is necessary to let the ends protrude through inlet 9 andoutlet 8. The invention suggests that specific hose couplings 26 arethen employed to enable connection of the ends of the hose to the inletand the outlet, respectively. By means of said hose couplings the largeforces necessary to position the ends correctly in the inlet and outlet,respectively, can easily be produced. Such a hose coupling isillustrated in detail in FIGS. 6A-C.

[0069] The hose coupling 26 comprises an inner retaining plate 27screwed onto the inside of the wall 12 of the pump housing 6A, 6B at theinlet 9 and the outlet 8, respectively. A socket 29 is insertable intothe end of the hose 25 placing the hose end against a flange 29A of thesocket. A hose clamp 31 may be provided to lock the hose end to thesocket 29. Furthermore, the hose coupling 26 comprises an outerretaining plate 28 adapted to be pushed onto the socket 29 from theoutside, up to the flange 29A. Then, clamp bolts 30 are inserted intothrough bores 28A in the outer retaining plate 28 and into alignedthrough bores in the housing wall 12 of the pump, at the inlet 9 and theoutlet 8, respectively, and into the inner retaining plate 27. Nuts arescrewed onto the clamp bolts, on the inner side of the inner retainingplate. By tightening the clamp bolts 30 the socket 29, and thereby thehose end, are pulled towards the housing wall 12 at the inlet andoutlet, respectively, since the outer retaining plate bears on theflange 29A. Thereby, the socket and the hose end ultimately engage thehousing wall with the flange clamped between the housing wall 12 and theouter retaining plate 28. This connection of the hose to the outlet 8 ofthe housing 6A by means of the retaining plates also provides protectionagainst the socket 29 being pushed out of the outlet 8 by a high pumppressure.

[0070] Although the invention has been described above with reference toan embodiment thereof particularly intended for mobile pump equipmentfor clean-up operations in difficult terrain, it should be emphasizedthat it also covers other variants using the basic principles of theinvention. Thus, it is likewise possible within the scope of theinvention to use these basic principles for a pump having a hosearranged in a loop of 180° and/or having more than one roller arm, eventhough it will slightly decrease the expected useful life.

[0071] The man skilled in the art recognizes that various modificationsand changes can be made to the invention without departing from thescope thereof, as defined by the appended claims.

1. A peristaltic pump (6) for pumping viscous and/or polluted media,comprising a housing (6A; 6B) having a substantially cylindrical wall(12) against which an elastic hose (25) is arranged in a loop around thecylindrical wall, a rotating shaft (7) centrally positioned in thehousing and carrying an inner end of a roller arm (13) that at the outerend thereof is provided with a roller (14) adapted to roll against andat the same time locally compress the hose (25) against the wall (12),characterized by a guide path (35) placed against the inner wall (12) ofthe housing (6A, 6B) and having an upper surface (35A) against which thehose (25) rests, in that the guide path (35) is made of a yieldingmaterial and in that it is impregnated with a lubricant.
 2. A pump (6)according to claim 1, characterized in that the guide path (35) consistsof cellular rubber forming a lubricant reservoir.
 3. A pump (6)according to claim 1 or 2, characterized in that the guide path (35)consists of a support ramp the upper surface (35A) of which has a slopeadapted to place the ends of the hose (25) in planes on top of eachother.
 4. A pump (6) according to claim 3, characterized in that theupper surface (35A) of the guide path (35) has a screw pitch.
 5. A pump(6) according to any of claims 1-4, characterized in that the roller(14) and the inner wall (12) of the housing (6A, 6B) are provided with alayer of a resilient material, preferably polyurethane.
 6. A pump (6)according to any of claims 1-5, characterized in that the length of theroller arm (13) supporting the roller (14) at its outer end, is linearlyadjustable in a radial direction with regard to the shaft (7).
 7. A pump(6) according to claim 6, characterized in that the roller arm (13) isprovided with a block (18) mounted on the shaft (7), fixed to rotatewith the shaft, and upper and lower guide plates (19, 20) that can beclamped together and that in the sides facing each other are providedwith guide grooves (19A, 20A) for slidable but lockable reception ofguide bars (16, 17) extending from a roller holder (15).
 8. A pump (6)according to claim 7, characterized by an adjusting plate (23) engagingrear ends of the guide bars (16, 17), on an opposite side of the pumpshaft (7) compared to the roller (14), and by an adjusting screw (24)that has a fine pitch, that extends through the adjusting plate (23) andthat is screwed into the block (18) for radial adjustment of the rollerholder relative to the pump shaft.
 9. A pump (6) according to any ofclaims 1-8, in which the hose (25) is arranged in a loop of at least360° against the cylindrical wall (12), whereby the ends of the hose areconnected to an inlet (9) and an outlet (8) of the pump(6),respectively, by means of a hose coupling (26), characterized in thatthe hose coupling (26) comprises a socket (29) insertable into andconnectable to the hose (25) and by inner and outer retaining plates (27and 28, respectively) adapted to clamp between them a flange (29A) ofthe socket (29) and the housing wall (12) of the pump at the inlet (9)and the outlet (8), respectively.
 10. A pump (6) according to claim 9,characterized in that the inner retaining plate (27) is fixed to theinlet (9) and the outlet (8) of the pump (6), respectively, at theinside thereof, and in that clamp bolts (30) extend through the innerand outer retaining plates (27 and 28, respectively) and the housingwall (12) of the pump at the inlet (9) and outlet (8), respectively,whereby tightening of the clamp bolts (30) brings the flange (29A) ofthe socket (29) to lie against the inlet, clamped between the housingwall and the outer retaining plate (28).
 11. A pump (6) according to anyof claims 1-10, characterized in that the hose (25) is formed of aninner layer (L1) of a first synthetic material resistant to the pumpedmedium, an outer layer (L2) of a second synthetic material resistant towear and to oil and ultraviolet radiation and therebetween at least onelayer (K1, K2) of compression rigid cord material, a layer (E) ofelongation rigid cord material and a layer (M) of highly elasticmaterial with low attenuation.
 12. A pump (6) according to claim 11,characterized in that the layer/layers (K1, K2) of compression rigidcord material comprises/comprise cord of macrofilament crossed at anangle (α) of about 120°, each at an angle (γ) of about 60° to thecentral axis (C) of the hose (25) and in that the layer (E) ofelongation rigid cord material comprises polyester cord crossed at anangle (β) of about 108°, each at an angle (λ) of about 54° to thecentral axis (C) of the hose.
 13. A pump (6) according to claim 11 or12, characterized in that outside the inner layer (L1) consisting of afirst synthetic material, preferably nitrile rubber, is provided a firstlayer (K1) of compression rigid cord material, then the layer (M) ofhighly elastic material, preferably natural rubber, a second layer (K2)of compression rigid cord material and, adjacent to the outer layer (L2)consisting of a second synthetic material, preferably chlorophrenerubber, the layer (E) of elongation rigid cord material.
 14. A pump (6)according to any of claims 11-13, characterized in that the hose (25)has a relationship between inner diameter (DI) and outer diameter (DY)of <0.56 and in that the layer (M) of highly elastic material has athickness (TS) of at least about 30% of the wall thickness (TV) of thehose.
 15. The use of a pump (1) according to any of claims 1-14 inmobile equipment for clean-up operations in remote areas.
 16. A guidepath (35) for use in a peristaltic pump (6) of the type comprising ahousing (6A, 6B) having a substantially cylindrical wall (12) againstwhich an elastic hose (25) is arranged in a loop around the cylindricalwall, a roller (14) supported centrally in the housing on a roller arm(13) and adapted to roll against and at the same time locally compressthe hose (25) against the wall (12), characterized in that it has anupper surface (35A) against which the hose (25) is adapted to rest, inthat the guide path (35) is made of a yielding material and in that itis impregnated with a lubricant.
 17. A guide path (35) according toclaim 16, characterized in that the guide path (35) consists of cellularrubber forming a reservoir for the lubricant.
 18. A guide path (35)according to claim 16 or 17, characterized in that it is designed as asupport ramp the upper surface (35A) of which has a slope adapted toposition the ends of the hose (25) in planes on top of each other.
 19. Aguide path (35) according to claim 18, characterized in that the uppersurface (35A) is formed having a screw pitch.
 20. A method oflubricating a peristaltic pump (6) for pumping viscous and/or pollutedmedia and comprising a housing (6A, 6B) having a substantiallycylindrical wall (12) against which an elastic hose (25) is arranged ina loop around the cylindrical wall, and a roller (14) supportedcentrally in the housing on a roller arm (13) and adapted to rollagainst and at the same time locally compress the hose (25) against thewall (12), characterized in that a guide path (35) for the hose (25) andmade of a yielding material is arranged in the housing (6A, 6B) adjacentto the substantially cylindrical wall (12) and in that a lubricantreservoir is formed in the guide path by impregnating it with thelubricant, thereby providing an intermittent lubrication of the hose andthe roller controlled by the rolling of the roller against the hose. 21.A method according to claim 20, characterized in that the guide path(35) is designed as a support ramp for the hose (25), and is formedhaving an upper surface (35A) against which the hose (25) is adapted torest and that is formed with a screw pitch.
 22. A method according toclaim 20 or 21, characterized in that the guide path (35) is made ofcellular rubber.